Improvement in cut-offs for steam-engines



UNITED STATES PATENT OFFICE.

J. H. PAINE, OF HARTFORD, CONNECTICUT.

IMPROVEMENT IN CUT-OFFS FOR STEAM-ENGINES.

Specification forming part of Letters Patent No. 46.020, dated January24, 1855.

To all whom it may concern Beit known that I, J. H. PAINE, ot' Hartford,in the county ot' Hartford and State of Connecticut, have invented a newand Improved Cut-ott; and I do hereby declare that the t'ollowingis afull,clear, and exactdescription thereof, which will enable othersskilled in the art to make and use the same, reference being had to theaccompanying drawings, forming part ot' this specification, in which-Figure l is a sectional side elevation of this invention. Fig. 2 is asectional plan of the same. Fig. 3 is a detached sectional view of thevalve-rod in a larger scale than the previous figures.

Similar letters of reference indicate like parts.

This invention consists in the employment or use of a spiral cam appliedin combination with the governor and with the main valve and cut-ott'valve of a steam-engine in such a manner that by the action of the camon the rod of the cut-oftl valve the steam is cut off instantaneously,(or nearly so,) and, the wire drawing ot' the steam is avoided, and,furthermore7 the cam being in action for a short space. of time, leavesthe governor free during the largest part of the stroke.

It consists, further, in the application ot' a latch and sliding pin, incombination with the rods of the main valve and of the cut-off valve andwith a suitable cam in such a manner that by the action of the latch themain and cut-off valves are locked open, leaving no liability to closethe ports until the proper time arrives, and by the action ot' the camand pin the two valves are disconnected instantaneously, allowing themto move in the same or in opposite directions as occasion may require.

A represents a steam-cylinder, which is provided with two steam-chests,B, one at each end, and each steam-chest contains a separateslide-valve, C, and cut-oft' valve D.

One end of the cylinder only is shown in the drawings; but the operationot' my cut-ott' will be readily understood from the followingdescription, since the valves at that end ofthe cylinder which is is notshown are operated by the same cam precisely in the same inanner asthose which are represented.

The cylinder takes steam through the port a in the valve-seat andthrough a corresponding channel, uit, in the main valve C, and itexhausts through the port b and corresponding cavity, bit, in the faceot' said valve, and

the channel ai is alternately closed and opened at the proper intervalsby the cut-oft' valve D.

The stem c ot' the main valve C is hollow and iirmly secured in astandard, E, which rises from a slide, F, to which a reciprocatingmotion is im parted by an eccentric, Gr, mounted on the spindle H ofthegovernor I, or by any other suitable means.

The cut-oft' valve D is iittcd steam-tight on the back ofthe main valveC, and itis provided with a channel, c', which can be brought toregister with the channel a* in the main valve or not, as circumstancesmay require. It' both channels register wholly or partially with theport a, steam passes into the cylinder; but it one of the two channelsor both do not register with said port steam is cut oft'.

The stem d of the cut-oft valve D extends through the hollow stem c ot1the main valve, and the two are locked together by a latch, e, which ishinged to the top of the standard E and drops in a notch,f, in thevalve-stem d. The position of the latch and notch in relation to eachother is such that when by their action the two valve-stems are lockedtogether, the channel at in the main valve registers with the channel ain the cutoff valve, or, in other words, the two valves are locked openand are not allowed to close before the specied time.

In order to release the latch automatically at the proper instant, apin, g, is titted into the end of the valve-stem, and a tlat spring, h,secured to the front end otl this pin, bears with its loose end on aninclined piane, i, under and behind the notch j', as shown in Fig. 3 ofthe drawings.

Itl by some pressure exerted on its head the pin g is driven back in itssocket, the spring h ascends the inclined plane i, and the `latch israised so as to clear the notch j', and when the pressure ceases thespring li, carries the pin back to its original position. This object iseffected automatically at the desired instant by a cam, J, which isarranged on the spindle H of the governor, so that it rises and fallsfreely on t-he same, but is compelled to rotate with it. Said cam isformed by a spiral iiange, which acts on the pin g during 'differentparts of the stroke, according to the higher or lower position of saidcam on the spindle of the governor. If the cam is moved down on thespindle as far as it will go7 steam is admitted during the full strokeof the piston 5 but if the cam is moved up to its central position steamis out o' at half-stroke, and if the cam is raised as high as it will gono steam at all is allowed to pass into the cylinder7 or steam is cutoff at full stroke.

It will be readily understood what the effect ofthe cam will be in itsintermediate positions, and if the cam is connected to the governor theposition of the cut-oft' valve will be regulated automatically accordingto the requisite speed of the engine. The connection of the cam andgovernor may be effected in a simple manner, and the action ot the camis such that it leaves the cam free during the largest part ot' itsrevolution, and the friction between the valves is nearly all removed,as the stem of the out-o'valve is held in contact with the cam onlyuntil the port is closed, and is then allowed to travel with the mainvalve. The

sensitiveness of the governor is thereby in creased and a more uniformspeed of the engine effected than with governors and cut-offs 0f theordinary construction.

An adjustable stop, j, is secured in the outer end of the steam-chest,which serves to retain the eut-oft' valve stationary. in the properposition while the main valve traverses under it. rlhis stop is soadjusted that the port in the cut-oft' valve will register with that inthe main valve until the action of the cam J on the pin g commences. l

I claim as new and desire to secure by Letters Patent- 1. The spiral camJ, applied in combination with the governor and with the main valve Cand cutoff valve B, substantially as and for the purpose set forth.

2. The sliding pin g and hinged latch e, in combination with the valvesC D and cam J, constructed and operating substantially as and for thepurpose described. A

J. H. PAlNE.

Witnesses Ron'r. W. HAMILTON, E. J. MURPHY.

